Résumé:
The aim of the study is to monitor the effect of adding the hydromethanic extract of Rosmarinus
officinalis (Rosemary) as a natural additive, on the variations in the quality of the Ouled Djellal leg of
lamb mutton obtained from steppe pasture during positive cold storage of 40C. The meat samples in 3
repetitions of 200 grams of leg of hen were processed at 0, 20, 40, 60, 80 and 100% of plant extract
respectively. A count of germs (total aerobic mesophilic flora, Staphylococcus aureus, psychrotrophic
flora and Pseudomonas aeroginosa and faecal coliforms) was carried out periodically at (1, 3, 5, and 7
th day) successively on the coldpreserved meat samples. . The experimental results were subjected to a
single-factor analysis of variance and a comparison of means. During the whole storage period,
compared to the control (control without additive), the meat treated with the pure hydromethanic
extract of Rosemary rich in phenolic compounds experienced significant declines (p˂0.01) in number
of the main germs tested; 93% for total aerobic mesophilic flora, 98% for faecal coliforms, 99.01% for
Staphylococcus aureus, 94% for psychrotrophic germs and 92% for Pseudomonas aeroginosa. The
pure extract as a natural additive maintained intact the quality of the meat microbiologically during 7
days of cold storage.
